1. Field of the Invention
The present invention relates, in general, to a slide pen having a pen core, a pen core slider, and a body casing, in which the pen core is moved in and out by means of the movement of a pen core slider coupled with a pen core held in the body casing.
2. Description of the Prior Art
In general, a writing implement comprises a pen core and spring, a pen core case, an operating button, and upper and lower cases.
In order to use the writing implement having this operating button, the operating button, located at an upper portion of the writing implement, is pressed to protrude the pen core. When use of the writing implement is complete, the operating button is again pressed to retract the pen core. Thereby, the writing implement enters a portable state.
This operating button is usually adapted to operate a lock and gear to protrude or retract the pen core.
More specifically, in a state where the lock and gear, which are interlocked with each other, are seated in a hooking recess in the upper case, when a user applies a predetermined force to the operating button, the lock and gear are detached from the locking recess, and thus rotate and move forward in the direction in which the operating button is pressed.
Then, when no force is applied to the operating button, the lock and gear rotate, and a protrusion of the gear is hooked on a hooked step of the upper case. This operation causes the pen core to be pushed downward by the force applied to the lock, and thereby the pen core protrudes outside the lower case.
In the opposite case, upon completion of use of the writing implement, when the user applies a predetermined force to the operating button again, the lock and gear are detached from the hooked step, and rotate and move forward in the direction in which the operating button is pressed.
Then, when no force is applied to the operating button, the lock and gear rotate, and are seated in the hooking recess of the upper case. This operation causes a resilient portion to be recovered from elastic deformation, and thereby the pen core is retracted into the lower case.
However, most of these lock-type writing implements include four or five constituent pieces, such as the pen core case, the operating button, the upper and lower cases, and so on, that is, they have many parts and a complicated structure, so that the production cost thereof is high, and assembly is difficult.